I tried a couple combinations and didn't find anything that worked well. Here's a tip - try the search page to see if you can get the right query first:
http://twitter.com/#!/search-home. There's an advanced query option too and you can watch what the query looks like through Fiddler. If that doesn't work, a potential hack is to do two queries
where the second excludes "#svcc", like this:
"@sv_code_camp OR @SV_CODE_CAMP -#svcc -#SVCC"
Polling works, as you see. Another option is to write a Windows Service with a timer.
The most efficient approach would be to use a filter stream - there are streaming examples in the downloadable code LinqToTwitterDemo. A stream gives you the status as soon as it's tweeted and you don't have to poll - I would do this as a Windows
Service. The stream approach is a fair amount of work in comparison to the polling you have in-place now.